Simplify the following expression: $k = \dfrac{-3n}{7n - 10} - \dfrac{-n + 8}{7n - 10}$
Answer: Since the expressions have the same denominator we simply subtract the numerators: $k = \dfrac{-3n - (-n + 8)}{7n - 10}$ Distribute the negative sign: $k = \dfrac{-3n + n - 8}{7n - 10}$ Combine like terms: $k = \dfrac{-2n - 8}{7n - 10}$